The attack took place as Prime Minister Nawaz Sharif's government is trying to engage Taliban militants in negotiations to end years of fighting. However, intensification in Taliban attacks dashed hopes for the continuation of the process.

Taliban Spokesman Shahidullah Shahid claimed the responsibility for the brazen late Sunday attack on the Karachi airport as a " revenge" for the killing of their leader, Hakimullah Mehsud, who was killed in a U.S. drone attack in North Waziristan in November last year.

Pakistanis could not comprehend the style of the Taliban in exacting revenge on Pakistani security forces and civilians, when the killing of Mehsud was done by the Americans.

As the attack in Karachi has almost buried the peace dialogue, the Tehrik-e-Taliban Pakistan (TTP) spokesman vowed more attacks in the future.

"It's just the beginning, we have taken revenge for one ( Hakimullah Mehsud), we have to take revenge for hundreds," Shahid said in a statement.

Shahid said that the Taliban will still have to take revenge for the deaths of hundreds of innocent tribal women and children in Pakistani air strikes.

The Taliban also issued a statement on Umar Media, the official media wing of the TTP, claiming on their Facebook page that only six militants had attacked the airport.

"The biggest reason for attacking Karachi airport is because it serves as the biggest air logistics center supplying goods for the Crusaders'war in Afghanistan and Pakistan," a statement on their Facebook page said.

The Taliban warning of more attacks indicates that they are no longer interested in the dialogue process and would opt for an armed confrontation with the authorities. This, in effect, would justify a massive military offensive by the Pakistani security forces in the Taliban's last stronghold in North Waziristan.

The Sharif government has earlier announced that it will respond to any act of terrorism using the full force of the military.

Support for the peace dialogue has been diminished. Now the government is under tremendous pressure to act against the Taliban after the Karachi airport attack and the Taliban announcement to carry out more terror attacks.

The opposition parties had previously thrown weight behind Sharif's policy to engage the Taliban in a peaceful dialogue. However the political leaders are now urging the government to opt for a decisive action.

Besides internal pressure, the United States has also mounted pressure on Pakistan to do more to establish itself in the border region to stop the militants from crossing into Afghanistan.

The U.S. and its Western allies will never want instability in the post-NATO Afghanistan and they insisted that Pakistan should dismantle what they call "safe heavens" of the militants in Waziristan.

The rare dialogue process started in February as Mr. Sharif wanted to find out a negotiated settlement out of the violent extremism that has claimed thousands of lives and resulted in the loss of billions of dollars in Pakistan's weak economy.

Despite sporadic attacks by the Taliban, the government kept the peace process on track.

A progress was also seen when a round of face-to-face negotiations was held between the Taliban leaders and a new government committee, but the Taliban's preconditions had a negative impact on the peace talks.

The Taliban had earlier said they would not put any condition but later they called for return of some areas in South Waziristan and the release of their prisoners. The government had rejected the two demands.